This places them perhaps even 10 million years before the "Cambrian Explosion" (roughly 541 million years ago), the moment in time which sparked the incredible evolution of life that led to the awesome diversity of species that we see today.
The shape of the tracks suggest they were made by bilaterian animals with pairs of legs and a raised body.
For comparison, non-bilateral animals include sponges, corals, jellyfish, and anemones.More news: ValuEngine Downgrades athenahealth (NASDAQ:ATHN) to Hold
The trackways reveal that a bilaterian animal - a creature with bilateral symmetry that has a head at one end, a back end at the other, and a symmetrical right and left side - such as arthropods and annelids made the tracks.
Unfortunately, the team hasn't got a complete fossil record, and they can not assess the habits or needs of the animal that left those 'footprints.' They didn't find the body fossils of the animal, and they might never find it, as preservation is highly unlikely after so much time.
Still, this discovery means that paleontologists will have to revise their vision of how life developed in Earth's primordial oceans. However, Xiao said they are uncertain if the creature belonged to the arthropod family or whether it has many or two legs.
"Previously identified footprints are between 540 and 530 million years old".More news: President could face questioning by next year in defamation suit
An global team of scientists, including researchers from the Nanjing Institute of Geology and Palaeontology, and Virginia Tech in the United States, conducted the study. "Also, they are organised in repeated groups, as expected if the animal had multiple paired appendages".
"Arthropods and annelids, or their ancestors, are possibilities".
However, the fossil record of animal appendages confirms that their evolutionary ancestry was rooted in the Ediacaran Period, the researchers noted. The fossil of the animal has not been found or maybe it never got preserved.More news: Ex-Senate intel aide charged after DOJ seizes reporter's records